Design and Fabrication of a Passivated, Semitransparent, and Anatomy-Conformable Wearable Sensor Using a Cost-Effective Encapsulation Process

Abstract

Wearable electrochemical sensors have emerged as a promising solution for continuous and noninvasive health monitoring. However, as these devices transition from laboratory prototypes to real-world applications, challenges related to reliability, safety, and long-term operation under direct skin contact become increasingly critical. In particular, inadequate encapsulation of conductive tracks and contact pads may lead to material degradation, reduced device lifetime, and potential risks to the user. This work presents a cost-effective encapsulation process for wearable electrochemical sensors, designed to ensure selective exposure of active electrode areas while fully passivating conductive interconnects and contact regions. The proposed approach is compatible with flexible substrates and scalable fabrication techniques, enabling the development of disposable and conformable devices for healthcare applications. To validate the method, a fully passivated, semi-transparent, and flexible sensor prototype is fabricated and experimentally evaluated. This encapsulation strategy provides a practical pathway toward reliable, low-cost, and user-safe wearable sensing systems.